Prion-Dependent Lethality of Missense Mutations Is Caused by Low GTPase Activity of the Mutant eRF3 Protein.

The essential gene encodes yeast translation termination factor Sup35/eRF3. The N-terminal domain of Sup35 is also responsible for Sup35 prionization that leads to generation of the [] prion. Previously we isolated different types of mutations (missense and nonsense) and demonstrated that nonsense mutations () are incompatible with the [] prion, leading to lethality of [] haploid cells.

NOS1AP Interacts with α-Synuclein and Aggregates in Yeast and Mammalian Cells.

The gene encodes a cytosolic protein that binds to the signaling cascade component neuronal nitric oxide synthase (nNOS). It is associated with many different disorders, such as schizophrenia, post-traumatic stress disorder, autism, cardiovascular disorders, and breast cancer. The NOS1AP (also known as CAPON) protein mediates signaling within a complex which includes the NMDA receptor, PSD-95, and nNOS.

The Human NUP58 Nucleoporin Can Form Amyloids In Vitro and In Vivo.

Amyloids are fibrillar protein aggregates with a cross-β structure and unusual features, including high resistance to detergent or protease treatment. More than two hundred different proteins with amyloid or amyloid-like properties are already known. Several examples of nucleoporins (e.

Chromosome-level genome assembly and structural variant analysis of two laboratory yeast strains from the Peterhof Genetic Collection lineage.

Thousands of yeast genomes have been sequenced with both traditional and long-read technologies, and multiple observations about modes of genome evolution for both wild and laboratory strains have been drawn from these sequences. In our study, we applied Oxford Nanopore and Illumina technologies to assemble complete genomes of two widely used members of a distinct laboratory yeast lineage, the Peterhof Genetic Collection (PGC), and investigate the structural features of these genomes including transposable element content, copy number alterations, and structural rearrangements. We identified numerous notable structural differences between genomes of PGC strains and the reference S288C strain.

Whole genome sequencing data and analyses of the underlying transcriptional regulation for a nonsense suppressor mutant.

Termination of translation in eukaryotes is governed by two release factors encoded by the and genes in . Previously, a set of mutations in these genes had been obtained. However, the exact sequence change associated with one mutation, , was not identified by Sanger sequencing of the region.

To CURe or not to CURe? Differential effects of the chaperone sorting factor Cur1 on yeast prions are mediated by the chaperone Sis1.

Yeast self-perpetuating protein aggregates (prions) provide a convenient model for studying various components of the cellular protein quality control system. Molecular chaperones and chaperone-sorting factors, such as yeast Cur1 protein, play key role in proteostasis via tight control of partitioning and recycling of misfolded proteins. In this study, we show that, despite the previously described ability of Cur1 to antagonize the yeast prion [URE3], it enhances propagation and phenotypic manifestation of another prion, [PSI ].

SFP1-mediated prion-dependent lethality is caused by increased Sup35 aggregation and alleviated by Sis1.

[PSI ] is the prion form of the translation termination factor Sup35 (eRF3); [PSI ] strains display nonsense suppression. Another prion-like element, [ISP ], is linked to antisuppression in a specific background. Transcriptional regulator Sfp1 was shown to be responsible for [ISP ] propagation.

The translation termination factor eRF1 (Sup45p) of Saccharomyces cerevisiae is required for pseudohyphal growth and invasion.

Mutations in the essential genes SUP45 and SUP35, encoding yeast translation termination factors eRF1 and eRF3, respectively, lead to a wide range of phenotypes and affect various cell processes. In this work, we show that nonsense and missense mutations in the SUP45, but not the SUP35, gene abolish diploid pseudohyphal and haploid invasive growth. Missense mutations that change phosphorylation sites of Sup45 protein do not affect the ability of yeast strains to form pseudohyphae.

The paradox of viable sup45 STOP mutations: a necessary equilibrium between translational readthrough, activity and stability of the protein.

The mechanisms leading to non-lethality of nonsense mutations in essential genes are poorly understood. Here, we focus on the factors influencing viability of yeast cells bearing premature termination codons (PTCs) in the essential gene SUP45 encoding translation termination factor eRF1. Using a dual reporter system we compared readthrough efficiency of the natural termination codon of SUP45 gene, spontaneous sup45-n (nonsense) mutations, nonsense mutations obtained by site-directed mutagenesis (76Q --> TAA, 242R --> TGA, 317L --> TAG).

Inactivation of NMD increases viability of sup45 nonsense mutants in Saccharomyces cerevisiae.

Background: The nonsense-mediated mRNA decay (NMD) pathway promotes the rapid degradation of mRNAs containing premature termination codons (PTCs). In yeast Saccharomyces cerevisiae, the activity of the NMD pathway depends on the recognition of the PTC by the translational machinery. Translation termination factors eRF1 (Sup45) and eRF3 (Sup35) participate not only in the last step of protein synthesis but also in mRNA degradation and translation initiation via interaction with such proteins as Pab1, Upf1, Upf2 and Upf3.

Viable nonsense mutants for the essential gene SUP45 of Saccharomyces cerevisiae.

Background: Termination of protein synthesis in eukaryotes involves at least two polypeptide release factors (eRFs) - eRF1 and eRF3. The highly conserved translation termination factor eRF1 in Saccharomyces cerevisiae is encoded by the essential gene SUP45.

Results: We have isolated five sup45-n (n from nonsense) mutations that cause nonsense substitutions in the following amino acid positions of eRF1: Y53 --> UAA, E266 --> UAA, L283 --> UAA, L317 --> UGA, E385 --> UAA.

Mouse GSPT2, but not GSPT1, can substitute for yeast eRF3 in vivo.

Background: The termination of protein synthesis in eukaryotes involves at least two polypeptide release factors (eRFs), eRF1 and eRF3. In mammals two genes encoding eRF3 structural homologues were identified and named GSPT1 and GSPT2.

Results: In the present study, we demonstrate that mouse mGSPT2 but not mGSPT1 could functionally substitute the essential yeast gene SUP35.